After looking around for a while, I discovered a freeware program called DoubleCommand that will do exactly this, and much more. DoubleCommand is a key mapping (or more appropriately, key REmapping) program originally designed for old PowerBooks that was created to add a secomd Command key, hence the name DoubleCommand. It's very powerful and user-friendly; check it out to add lots of nice tweaks.
[robg adds: We mentioned DoubleCommand way back in October of 2001, but with the number of "where's the forward delete key on my MB/MBP?" questions I've been receiving from recent switchers, I figured it was worth a re-mention. If you're a laptop user, it's definitely worth a look.]

